1. Institute of Social and Preventive Medicine (I.S.P.M.), University of Bern, 3012 Bern, Switzerland
2. Graduate School for Health Sciences, University of Bern, 3012 Bern, Switzerland
3. Navarra Institute for Health Research (IdiSNA), 31009 Pamplona, Spain
4. Faculty of Health Sciences and Medicine, University of Lucerne, 6005 Lucerne, Switzerland
5. Medical Library, University of Bern, 3012 Bern, Switzerland
6. Instituto Proinapsa, Universidad Industrial de Santander, Bucaramanga 680002, Colombia
7. Epistudia, 3008 Bern, Switzerland
8. Swiss Paraplegic Research, 6207 Nottwil, Switzerland
9. Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands
10. Department of Medicine, Internal Medicine, Lausanne University Hospital (C.H.U.V.) and University of Lausanne, 1011 Lausanne, Switzerland